package captcha

import (
	"crypto/rand"
	"image"
	"math/big"
	"time"

	"github.com/pkg/errors"
)

const (
	maxAnswer = 999999
)

var errorNotFound = errors.New("captcha not found")

type ID string
type Answer string

type ICaptcha interface {
	GenerateImage() *image.Image
	GetImage() *image.Image
	GetAnswer() Answer
	Solve(answer Answer) bool
	IsSolved() bool
	Expire() time.Time
}

type Captcha struct {
	Image    image.Image
	Answer   Answer
	Solved   bool
	ExpireIn time.Time
}

func GenerateAnswer() Answer {
	ans, _ := rand.Int(rand.Reader, big.NewInt(maxAnswer))
	return (Answer(ans.String()))
}

func ExpireDate(expiration time.Duration) time.Time {
	return time.Now().Add(expiration)
}